The Waterberg Massif, Limpopo Province, South Africa
C. Michael Hogan, Mark Cooke and Helen Murray lumina technologies
May 11, 2006
The Waterberg Massif is a biosphere preserve situated in the extreme north of the Limpopo Province of South Africa. It comprises a land area of approximately 15,000 square kilometers Formed by an ancient geological uplift, the massif was deeply carved by hundreds of millions of years of riverine erosion to yield the myriad of bluff and butte landforms that house the resulting dry deciduous forest and its associated diverse riparian zones. Ecologically it is a Bushveld or tropical savanna biome. The Waterberg is the first region in northern South Africa designated as a Biosphere Reserve by UNESCO, receiving such status in the year 2001. Current research continues to reveal the rich heritage not only of its ecology, but also of the very evolution and prehistory of man, whose traces have long imbued this region.
The Kaapvaal Craton was formed as a precursor island approximately 2.7 billion years ago This stable thick crustal structure became the base of the Waterberg, which was further transformed by upward extrusion of igneous rocks from deep within the earth.. These extruded rock formations, generously endowed with minerals such as vanadium and platinum, are known as the Bushveld Igneous Complex. The resulting extent of this massive rock upthrust amounted to about 250,000 square kilometers, and is sometimes called the Waterberg Supergroup.
Since the earth's atmosphere became oxygenated about two billion years ago, the granite rocks were oxidized as they weathered and eroded, yielding a mosaic of red and purple coarse sands high in manganese and iron content. As eroded bedload material, these sands were transported lower by complex networks of slender streams and built the sedimentary strata evident today. This chapter of sedimentary deposition continued until about 1.5 billion years ago.
When the Kaapvaal Craton collided with the supercontinent Gonwanaland 250 million years ago, new erosion of the sedimentary layers was causing conspicuous elevation reduction of the Waterberg Supergroup, a process continuing through the time of splitting Gondwanaland into its present day continents starting about 180 million years ago. Sudden uplifts twenty million and five million years ago reversed the erosion trend and produced uplifted Waterberg Massif elevations of up to 500 meters higher than the 20 million BC landform prior to these recent uplifts (Taylor, 2003)..
Present day Waterberg is the core of the described geomorphic change, presenting mesas, buttes and occasional koppie granitic outcroppings. Some of the resulting exposed cliff faces tower 550 meters above the plains, manifesting the ancient colourful horizontally layered hard sandstone.
Prehistoric man at Waterberg
Considerable rainfall (in the earlier age) and the ability of sandstone to retain ample aquifers provided a hospitable habitat for early man. The table rock formations and cliff overhangs offered natural shelters and even caves for these original peoples. The first human ancestors probably inhabited Waterberg as early as three million years ago, since Makapansgat, only 40 kilometers to the east has yielded skeletons of Australopicthecus africanus dating above three million Homo erectus remains dating to one million years were also discovered in Makapansgat. A. Africanus, subsisting on plants and invertebrates, probably lived on valley floors; however, H. Erectus, a hunter, may have purposefully moved into the higher areas of the Waterberg for summer (December to March) game. At the periphery of the Waterberg in Olieboomsport later Acheulian artifacts were found, indicative of the early stone age of man. The earliest hard evidence of man in the heart of Waterberg (at Goudriver) is from the Middle Stone Age, where stone tools in cave shelters have been dated at 200,000 to 30,000 BC.
Bushman rock painting circa 8000 BC on cliffs above Palala River, midway in elevation between river and blufftop.
Bushmen from the Botswana region migrated south to the Waterberg about the time of Christ. They left rock paintings at Lapala and Goudriver recording their life and times, including characterizations of rhinoceros, elephant and a variety of antelope species (resembling impala, kudu and eland, all present day inhabitants). Early Iron Age settlers in Waterberg by 450 AD were the Bantu, an advanced tribe skilled in metal-working and cattle herding. The Bantu migrated from Nigeria, but their arrival with cattle created an environmental disaster in the lower plains around Waterberg, since cattle grazing decreased grasses in favour of increasing certain brush species conducive to reproduction of the tse-tse fly. The resulting epidemic of sleeping sickness depopulated the human settlements on the plains, but life on the Waterberg Massif itself thrived, since the fly cannot tolerate altitudes exceeding 600 meters.
Influence of white settlers
The first white settlers reached Waterberg in the year 1808 led by Dr. Andrew Cowan. Although these first europeans did not endure, other caucausian settlers followed including the Swedish naturalist Aja Wohlberg in 1844. Fleeing increasing English discrimination in Capetown during the 1840s, a group of Dutch travellers set out in search of Jerusalem. When they arrived at the Waterberg, they reckoned they had reached as far as Egypt, by the appearance of the stark landforms The river name endured to the 21st century.
After other fierce battles between Dutch settlers and indigenous African peoples, the races existed peaceably alongside each other by the late 1800s. Unfortunately, the Dutch brought increased pressure of cattle grazing that added to the scale of such grazing methods used by indigenous tribes. By the year 1900 there were only 200 western inhabitants of the Waterberg (Encyclopedic, 1906), but the toll of grassland loss coupled with game hunting was beginning to have an impact upon native wildlife populations.
There are several discrete habitats within this biome known as the Waterberg Biosphere, which is fundamentally a deciduous dry forest. These sub-habitats are, high plateau savanna, specialized shaded cliff vegetation system and riparian zone habitat with associated marshes.
High plateau savanna is actually more of a low density semi-scrub forest, holding alternatively expansive rolling grasslands and low canopy semi-deciduous forest. Open canopy heights range from four to ten meters. This landscape provides sweeping vistas looking through silhouettes of Mountain seringa (Kirkia wilmsii), Acacia caffra, Silver- leaf terminalia (Terminalia sericea), Lavender tree (''Hetropixis natalensis''), Round-leaf teak, and other characteristic trees such as Peeling-bark tree (Ochna pulchra).
The The tree canopy of the Waterberg Biosphere is mostly leafless during the cold dry winter (June through September); moreover, in the summer months approximately 50 centimeters of rainfall. Exceptions to the winter drabness include the Dombeya tree that presents profuse late winter creamy white blossoms that contrast with the few remaining leaves of deep rust and brown. Another colourful late blooming species is the Sacred coral tree (Erythrina lysistemon), which produces elaborate blazes of red flowers in August. Indigenous grasses include Signal grass (Brachiaria serrata), Goose grass (Potentilla anserina} and Heather-topped grass. These and other indigenous grasses provide important graze infrastructure to support native bovids including impala, kudu, klipspringer, Blue wildebeast, heartbeast, blesbuck and other antelopes.
Other indigenous mammals of the plateau include giraffe, white rhinoceros, warthog and mongoose. Snakes present include the black mamba, spitting cobra and puff adder. As early as 1905 naturalist Eugene Marais studied these snakes as well as baboon troops of the Waterberg plateaus (Marais, 1937). Some birds seen are the Black-headed oriole and the White-backed vulture (Gyps africanus), who may be seen devouring the soft parts of dead game animals (Hawthorne, 1998).
Vegetative cliff habitats are abundant in the Waterberg due to the long geologic time of riverine erosion cutting vertical gorges through the sedimentary rock. Since the rock has been laid down in layers, horizontal clefts are ubiquitous so that a variety of shaded and sheltered habitats result. A very interesting wild occupant is the African porcupine (Hystrix cristata), who enjoys the privacy and protection of these cliffside caves. He may often be seen backing out of the caves, his defensive body orientation, as quills are pointed to his rear.
There are some unusual trees that have adapted to the cliff areas, including the Paper tree (Gmelina spp.), whose elegant thin flaking bark hangs from the thick trunks of specimens clinging to cliffsides above winding streams below. These can be seen especially well in the Lapalala Wilderness on bluffs above the Palala River. Another featured tree in this habitat is the Tree of life and death or fever tree. This tree was believed by Bushmen to have spiritual powers of enabling communication with dead ancestors. It is found among the sandstone layers on cliffs above the Palala River including one site believed to be used for such ancient ritual ceremonies and the location of some well preserved rock paintings. Birds found in the cliffside areas include the Black-headed oriole.
Riparian zones are associated with the four rivers and their tributaries that drain the Waterberg massif. These surface waters all drain to the Limpopo River which rises in the arid deserts to the west and flows easterly to discharge into the Indian Ocean. Red bushwillow is a staple riparian tree in this habitat. These riparian zones represent special niches in this water thirsty land and provide habitats for birds, reptiles and mammals that require more moist habitat than the high plateau affords.
In the waters themselves can be found the apex predator Nile crocodile and relaxing in river pools is the hippopotamus, especially in the Lepalala Wilderness area. These riverine habitats are unusually devoid of water-related insects such as water mites or mosquitos and the Waterberg is generally considered a Malaria-free region. This outcome presumably is associated with the dry climate and the absence of significant ponds or other standing pools.
==Current day conservation==
Presently about 77,000 people inhabit the Waterberg Biosphere. Politically the Waterberg lies in the Bushveld district of the Limpopo Province of South Africa. After cattle grazing brought a nadir of ecosystem health in the mid 1900s, the inhabitants gradually became aware of the advantages of restoring habitat to accommodate the original species of antelope, other bovids, black and white rhino, giraffe, hippopotami, warthogs and other important species whose numbers declined with the advent of cattle.
The steady rise in eco-tourism has fueled the interest in game farming and land conservation practices to restore aboriginal species to the Waterberg. Land management practices required are expensive and labour intensive, but repay the landowner with dividends of added value of precious wildlife habitat. There is also a trend of accumulating larger landholdings with the resultant advantage of fence removal in some large land tracts. This outcome is not only beneficial large mammal migration, but affords better gene pool interactions for genetically favourable outcomes of breeding among populations of mammals. Some of the specific techniques of land restoration are the reduction of invasive or non-productive shrubs, which tend to out-compete native grasses needed for successful grazing of bovids.
Tracey Hawthorne, Common Birds of South Africa, Struik Publishing, South Africa (1998) ISBN 1-86872-120-5
Eugene Marais, Soul of the Ape, Human and Rousseau (1937)
The Encyclopedic History of the Transvaal, Praagh and Lloyd, Johannesberg (1906)
William Taylor, Gerald Hinde and David Holt-Biddle, The Waterberg, Struik Publishers, Capetown, South Africa (2003) ISBN 1-86872-8226